The present invention relates to a method of producing strip stacks, also referred to as mat packets, from sheets or panels of adhesive material which are covered with release layers, particularly SMC resin mat panels. A sheet of material is advanced sequentially past a clamping device and a release layer removing device to a cutting member. The sheet is advanced a longitudinal distance corresponding to the desired width of a mat strip to be produced, the release layers are removed, and the sheet is held in the clamping device and cut to form the mat strip which is then deposited on a transporting member. The process is repeated such that a plurality of mat strips are deposited in a vertical stack one on top of one another to thus form a mat packet. The invention further relates to an apparatus for implementing the method including a feed device for advancing the sheet or panel of material past a clamping device into the region of a cutting member. The apparatus further includes a release layer removing device positioned between the clamping device and the cutting device, and a vertically and horizontally movable transporting member which can be moved underneath the mat strips which are produced.
In order to economically produce molded components from the hardenable molding material involved here, which is referred to as SMC or sheet molding compounds, by means of pressing tools, it is desirable to substantially automate the process steps between the storage of the sheet or panel of material in its preliminary form and the feeding of the sheet or panel, in the form of mat packets, to a pressing tool.
In the prior art methods and apparatus, the SMC resin mat panel, which is normally wound or coiled in rolls and covered with release layers, is unwound by means of a feeding device equipped with feed rollers, the release layers are removed, and a cutting member cuts the material into mat strips of a suitable length which are referred to as blanks. By depositing or stacking several mat strips on top of one another, a mat packet is formed which is then processed in a pressing or deforming tool.
In the prior art, the mat strip produced in the cutting process rests on a transporting member such as a conveyor belt, a plurality of mutually parallel narrow conveyor belts or a pusher strip. The mat strip to be processed is taken from the transporting member by suction or by needle grippers and is deposited at a stacking station, where a mat packet is formed by the superposition of several mat strips on one another.
The drawback of this type of method and apparatus is that a relatively long period of time is required to form the mat packet and the devices for picking up and transporting the mat strips are technically complicated. Furthermore, the adhesive properties of the mat strips often result in the strips becoming soiled.